ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

Objective: Huntington’s disease (HD) is characterized by motor, cognitive, and neuropsychiatric symptoms. Oculomotor impairments and gait variability have been independently considered as potential markers in HD. However, an integrated analysis of eye movement and gait is lacking. We performed multiple examinations of eye movement and gait variability in HTT mutation carriers, analyzed the consistency between these parameters and clinical severity, and then examined the associations between oculomotor impairments and gait deficits. Methods: We included 7 patients with pre-HD, 30 patients with HD and 30 age-matched controls. We collected demographic data and assessed the Unified Huntington’s Disease Rating Scale (UHDRS) score. Examinations, including saccades, smooth pursuit tests, and optokinetic (OPK) tests, were performed to evaluate eye movement function. The parameters of gait include stride length, walking velocity, step deviation, step length, and gait phase. Results: HD patients have significant impairments in the latency and velocity of saccades, the gain of smooth pursuit, and the gain and slow phase velocities of OPK tests. Only the speed of saccades significantly differed between pre-HD patients and controls. There are significant impairments in stride length, walking velocity, step length, and gait phase in HD patients. The parameters of eye movement and gait variability in HD patients were consistent with the UHDRS scores. There were significant correlations between eye movement and gait parameters. Conclusion Our results show that eye movement and gait are impaired in HD patients and that the speed of saccades is impaired early in pre-HD. Eye movement and gait abnormalities in HD patients are significantly correlated with clinical disease severity.

Background: and Purpose This study aimed to investigate the association between residual inflammatory risk (RIR) and vulnerable plaques using high-resolution magnetic resonance imaging (HRMRI) in symptomatic intracranial atherosclerotic stenosis (ICAS). Methods: This retrospective study included 70%–99% symptomatic ICAS patients hospitalized from January 2016 to December 2022. Patients were classified into four groups based on high-sensitivity C-reactive protein (hs-CRP) and low-density lipoprotein cholesterol (LDL-C): residual cholesterol inflammatory risk (RCIR, hs-CRP ≥3 mg/L and LDL-C ≥2.6 mmol/L), RIR (hs-CRP ≥3 mg/L and LDL-C <2.6 mmol/L), residual cholesterol risk (RCR, hs-CRP <3 mg/L and LDL-C ≥2.6 mmol/L), and no residual risk (NRR, hs-CRP <3 mg/L and LDL-C <2.6 mmol/L). Vulnerable plaque features on HRMRI included positive remodeling, diffuse distribution, intraplaque hemorrhage, and strong enhancement. Results: Among 336 included patients, 21, 60, 58, and 197 were assigned to the RCIR, RIR, RCR, and NRR groups, respectively. Patients with RCIR (adjusted odds ratio [aOR], 3.606; 95% confidence interval [CI], 1.346–9.662; P=0.011) and RIR (aOR, 3.361; 95% CI, 1.774–6.368, P<0.001) had higher risks of strong enhancement than those with NRR. Additionally, patients with RCIR (aOR, 2.965; 95% CI, 1.060–8.297; P=0.038) were more likely to have intraplaque hemorrhage compared with those with NRR. In the sensitivity analysis, RCR (aOR, 2.595; 95% CI, 1.201–5.608; P=0.015) exhibited an additional correlation with an increased risk of intraplaque hemorrhage. Conclusion In patients with symptomatic ICAS, RIR is associated with a higher risk of intraplaque hemorrhage and strong enhancement, indicating an increased vulnerability to atherosclerotic plaques.

Background: s/Aims: Non-invasive models stratifying clinically significant portal hypertension (CSPH) are limited. Herein, we developed a new non-invasive model for predicting CSPH in patients with compensated cirrhosis and investigated whether carvedilol can prevent hepatic decompensation in patients with high-risk CSPH stratified using the new model. Methods: Non-invasive risk factors of CSPH were identified via systematic review and meta-analysis of studies involving patients with hepatic venous pressure gradient (HVPG). A new non-invasive model was validated for various performance aspects in three cohorts, i.e., a multicenter HVPG cohort, a follow-up cohort, and a carvediloltreating cohort. Results: In the meta-analysis with six studies (n=819), liver stiffness measurement and platelet count were identified as independent risk factors for CSPH and were used to develop the new “CSPH risk” model. In the HVPG cohort (n=151), the new model accurately predicted CSPH with cutoff values of 0 and –0.68 for ruling in and out CSPH, respectively. In the follow-up cohort (n=1,102), the cumulative incidences of decompensation events significantly differed using the cutoff values of <–0.68 (low-risk), –0.68 to 0 (medium-risk), and >0 (high-risk). In the carvediloltreated cohort, patients with high-risk CSPH treated with carvedilol (n=81) had lower rates of decompensation events than non-selective beta-blockers untreated patients with high-risk CSPH (n=613 before propensity score matching [PSM], n=162 after PSM). Conclusions Treatment with carvedilol significantly reduces the risk of hepatic decompensation in patients with high-risk CSPH stratified by the new model.

Electroencephalogram (EEG) is a non-invasive, high temporal-resolution technique for monitoring brain activity. However, affected by the volume conduction effect, EEG has a low spatial resolution and is difficult to locate brain neuronal activity precisely. The surface Laplacian (SL) technique obtains the Laplacian EEG (LEEG) by estimating the second-order spatial derivative of the scalp potential. LEEG can reflect the radial current activity under the scalp, with positive values indicating current flow from the brain to the scalp (“source”) and negative values indicating current flow from the scalp to the brain (“sink”). It attenuates signals from volume conduction, effectively improving the spatial resolution of EEG, and is expected to contribute to breakthroughs in neural engineering. This paper provides a systematic overview of the principles and development of SL technology. Currently, there are two implementation paths for SL technology: current source density algorithms (CSD) and concentric ring electrodes (CRE). CSD performs the Laplace transform of the EEG signals acquired by conventional disc electrodes to indirectly estimate the LEEG. It can be mainly classified into local methods, global methods, and realistic Laplacian methods. The global method is the most commonly used approach in CSD, which can achieve more accurate estimation compared with the local method, and it does not require additional imaging equipment compared with the realistic Laplacian method. CRE employs new concentric ring electrodes instead of the traditional disc electrodes, and measures the LEEG directly by differential acquisition of the multi-ring signals. Depending on the structure, it can be divided into bipolar CRE, quasi-bipolar CRE, tripolar CRE, and multi-pole CRE. The tripolar CRE is widely used due to its optimal detection performance. While ensuring the quality of signal acquisition, the complexity of its preamplifier is relatively acceptable. Here, this paper introduces the study of the SL technique in resting rhythms, visual-related potentials, movement-related potentials, and sensorimotor rhythms. These studies demonstrate that SL technology can improve signal quality and enhance signal characteristics, confirming its potential applications in neuroscientific research, disease diagnosis, visual pathway detection, and brain-computer interfaces. CSD is frequently utilized in applications such as neuroscientific research and disease detection, where high-precision estimation of LEEG is required. And CRE tends to be used in brain-computer interfaces, that have stringent requirements for real-time data processing. Finally, this paper summarizes the strengths and weaknesses of SL technology and envisages its future development. SL technology boasts advantages such as reference independence, high spatial resolution, high temporal resolution, enhanced source connectivity analysis, and noise suppression. However, it also has shortcomings that can be further improved. Theoretically, simulation experiments should be conducted to investigate the theoretical characteristics of SL technology. For CSD methods, the algorithm needs to be optimized to improve the precision of LEEG estimation, reduce dependence on the number of channels, and decrease computational complexity and time consumption. For CRE methods, the electrodes need to be designed with appropriate structures and sizes, and the low-noise, high common-mode rejection ratio preamplifier should be developed. We hope that this paper can promote the in-depth research and wide application of SL technology.

Objective To reveal the molecular mechanism by which nuclear epidermal growth factor receptor(nEGFR)synergistically regulates the expression of cell migration-inducing protein(CEMIP)by forming a complex with the transcription factor Yin Yang 1(YY1),and to investigate the biological functions of the nEGFR-YY1-CEMIP signaling axis in invasion of hepatocellular carcinoma(HCC).Methods After HCC cells were serum-starved for 24 h,the cells were treated with 100 ng/mL EGF.Thus,the cells were divided into a control group and EGF-treated groups at different time points.Nuclear expression and localization changes of EGFR were detected by Western blotting and immunofluorescence(IF).To investigate the interaction between nEGFR and YY1,their nuclear colocalization and interaction were examined by IF and co-immunoprecipitation(Co-IP),respectively.Transcriptional profiling was performed using RNA sequencing(RNA-seq)to identify differentially expressed genes at the genome-wide level.Combined with Gene Ontology(GO)functional enrichment analysis and transcription factor binding profiles via using the JASPAR database,CEMIP was identified as a candidate target gene.To validate the regulatory mechanism,the following experimental groups were established,Control,EGF,siYY1,and siYY1+EGF.The expression of CEMIP at protein and mRNA levels was detected by Western blotting and RT-qPCR.To elucidate the molecular mechanism of nEGFR/YY1 binding to the CEMIP promoter,the control and EGF-treated groups were established.Chromatin immunoprecipitation followed by quantitative PCR(ChIP-qPCR)was performed to assess the enrichment of nEGFR/YY1 at the CEMIP promoter region.Luciferase reporter assay was conducted following transfection with either wild-type EGFR(EGFR-WT),nuclear localization-deficient mutant(EGFR-dNLS),YY1 overexpression plasmid(YY1-OE),or dominant-negative YY1 mutant(YY1-DN)to evaluate changes in promoter activity.Subsequently,cell migration and invasion capabilities were evaluated using scratch wound healing assay and Transwell assay,while hyaluronic acid(HA)level was quantified by ELISA.The expression of matrix metalloproteinases(MMP2/9)was analyzed via Western blotting to assess the regulatory role of the nEGFR/YY1-CEMIP axis in the migration and invasion of HCC cells.By analyzing the CEMIP expression profiles in HCC patients from National Center for Biotechnology Information(NCBI)public databases,its potential association with tumor metastasis risk was validated.Results Western blotting and IF demonstrated that EGF treatment significantly induced nuclear translocation of EGFR,peaking at 30 min(P<0.001).Co-IP and IF assays indicated both physical interaction and nuclear co-localization between nEGFR and YY1.RNA-seq analysis identified CEMIP as a significantly differentially expressed gene.GO enrichment analysis revealed that CEMIP was significantly enriched in biological processes related to cell invasion promotion.JASPAR prediction identified conserved YY1 potential binding region within the CEMIP promoter region.Western blot and RT-qPCR analyses confirmed that EGF treatment up-regulated CEMIP at both protein and mRNA levels(P<0.05).Notably,YY1 knockdown significantly suppressed CEMIP expression,while exogenous EGF supplementation restored CEMIP level in YY1-deficient cells(P<0.05).ChIP-qPCR analysis demonstrated specific enrichment of the nEGFR/YY1 complex at the CEMIP promoter region,with EGF stimulation significantly enhancing its binding affinity(P<0.001).Luciferase reporter assay confirmed that nEGFR/YY1 robustly enhanced CEMIP promoter activity(P<0.01),while either the EGFR-dNLS or the YY1-DN substantially attenuated this transcriptional activation.Functional phenotyping showed that the nEGFR/YY1-CEMIP axis significantly enhanced the migration and invasion of HCC cells by promoting HA catabolism and up-regulating MMP2/9 expression(P<0.05).Analysis of NCBI datasets revealed that CEMIP expression was significantly up-regulated in HCC tumor tissues than adjacent normal tissues(P<0.001).Moreover,HCC patients with elevated CEMIP expression exhibited higher risk of metastasis(P<0.001).Conclusion nEGFR promotes HCC invasion by forming a transcriptional complex with YY1 to cooperatively activate CEMIP expression.

Objective To reveal the mechanism by which the programmed death-ligand 1(PD-L1)-protein tyrosine phosphatase 1B(PTP1B)-focal adhesion kinase(FAK)signaling axis promotes the progression of hepatocellular carcinoma(HCC)and elucidate its effector functions in HCC.Methods GEPIA database was used to plot a 10-year survival curve for PD-L1 and FAK expression levels in HCC patients.Immunohistochemical(IHC)staining was utilized to analyze the relative expression levels of PD-L1 and FAK phosphorylated at the Y397 site[p-FAK(Y397)]in HCC tissues,and the results were compared to those in the adjacent non-tumor tissues.Subsequently,endogenous PD-L1 expression was detected with Western blotting in HCC cell lines with low(SNU-387)and high(Hep3B)PD-L1 expression levels.After lentivirus-transduced SNU-387PDL1+and Hep3BPDL1-cells were constructed,the effect of high and low expression of PD-L1 on the expression of p-FAK(Y397)with Western blotting.To elucidate the functional mechanism of FAK in HCC,functional rescue experiments were performed by administering a FAK inhibitor to SNU-387PDL1+cells and a FAK activator to Hep3BPDL1-cells,combined with wound healing scratch assay,Transwell invasion assay,EdU proliferation assay,and colony formation assay to evaluate tumor malignant effects.The GENEMANIA database predicted functional interactions between protein tyrosine phosphatase 1B(PTP1B),PD-L1,and FAK.IHC staining was performed to analyze the correlation among PD-L1,PTP1B,and p-FAK(Y397)expression.Co-immunoprecipitation(Co-IP)and indirect immunofluorescence(IF)were applied to validate the interaction between PD-L1 and PTP1B.Western blotting was utilized to confirm the regulatory relationship between PD-L1 and PTP1B.In vitro PTP1B phosphatase activity assay measured the changes in PTP1B activity.Subsequently,Western blotting was used to screen cell lines with high endogenous PTP1B expression(SNU-387)and low endogenous PTP1B expression(Hep3B).Furthermore,Hep3BPTP1B+and SNU-387PTP1B-cell lines were generated,and then p-FAK(Y397)levels were then detected in these modified cell lines,and the aforementioned functional effect assays(migration,invasion,proliferation and colony formation)and rescue experiments were repeated.Furthermore,Western blotting was employed to detect changes in downstream signaling pathways following enhancement or attenuation of p-FAK(Y397)in SNU-387 and Hep3B cells.Results IHC staining revealed a positive correlation between PD-L1 and p-FAK(Y397)expression in HCC tissues(95%CI:1.065～3.801,P<0.01).In SNU-387PDL1+cells,PD-L1 overexpression significantly enhanced phosphorylation at the FAK Y397 site(P<0.01)and increased cell migration,invasion,proliferation,and colony formation capabilities(P<0.01),and these effects could be reversed by FAK inhibitor treatment(P<0.05).Conversely,in Hep3BPDL1-cells,PD-L1 knockdown significantly reduced FAK Y397 phosphorylation(P<0.01)and decreased cell migration,invasion,proliferation,and colony formation abilities(P<0.01),and these effects were restored by FAK activator treatment(P<0.05).IHC staining further showed a negative correlation between PTP1B expression and both PD-L1 and p-FAK(Y397)in HCC tissues(95%CI:1.886～3.514,P<0.05).Co-IP and IF assays confirmed a direct interaction between PD-L1 and PTP1B,with PD-L1 suppressing PTP1B expression level and reducing its activity(P<0.01).In SNU-387PTP1B-cells,PTP1B knockdown significantly increased FAK Y397 phosphorylation(P<0.01)and enhanced cell migration,invasion,proliferation,and colony formation(P<0.01),and these effects were reversed by FAK inhibitor(P<0.05).While in Hep3BPTP1B+cells,PTP1B overexpression significantly decreased FAK Y397 phosphorylation(P<0.01)and reduced cell migration,invasion,proliferation,and colony formation(P<0.01),and those effects were restored by FAK activator treatment(P<0.05).Furthermore,enhanced phosphorylation at the FAK Y397 site in SNU-387 cells activated downstream PI3K/AKT and MEK/ERK signaling pathways(P<0.01),whereas inhibition of FAK(Y397)phosphorylation in Hep3B cells attenuated the activation of these signaling pathways(P<0.01).Conclusion PD-L1 activates FAK by suppressing PTP1B,thereby promoting migration,invasion,and proliferation in HCC.

The blue fluorescent carbon dots(TMCDs)and cyan fluorescent carbon dots(TMCDs-H2O)were synthesized fromm-phenylenediamine and tricarballylic acid through air-assisted melting polymerization and one-step hydrothermal method,respectively.Air purging could effectively inhibit the side reactions and reduce the derivative structures in the carbon dots product.The structure and morphology of these two materials were systematically characterized using liquid nuclear magnetic resonance spectroscopy(NMR),mass spectrometry(MS),and transmission electron microscopy.Compared to TMCDs-H2O((3.12±0.63)nm),TMCDs showed a smaller average particle size(approximately(1.85±0.02)nm).The NMR and MS analysis revealed that although the main structure of both types of carbon dots was similar,TMCDs exhibited a simpler structure with higher degree of polymerization.These results suggested that supramolecular interactions might introduce numerous small molecule derivatives into TMCDs-H2O particles,resulting in lower polymerization degree,multiple substructures,and larger particle size characteristics for this material.When employed as chemical sensors for metal ion detection,in the linear range of 1×10-5-5×10-4 mol/L,the detection limits of Fe3+by TMCDs and TMCDs-H2O were 3.3×10-6 mol/L and 3.8×10-6 mol/L,respectively.The experimental results demonstrated that the recoveries of CDs and inductively coupled plasma optical emission spectrometer(ICP-OES)were similarity,whereas TMCDs displayed a considerable relative standard deviation.This study demonstrated that endogenously derived structures in CDs could enhance the performance of metal ion sensing.

A matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS)method was developed for simultaneous analysis of 10 kinds of aphrodisiac drugs,including sildenafil,acetildenafil,nor-acetildenafil,homosildenafil,lodenafil carbonate,sildlenafil dimer impurity,vardenafil dimer,hydroxyacetildenafil,N-desmethylsildenafil and udenafil.By using different matrices(α-cyano-4-hydroxycinnamic acid(HCCA)and sinapic acid(SA)),the effects of solvents,amount of matrices,laser intensity and spotting methods on the peak strength and signal intensity of MALDI-TOF MS for the aphrodisiac drugs were investigated.As a result,SA was chosen as the matrix,and then dispersed in methanol-water(50∶50,V/V),and spotted by matrix firstly and sample secondly approach with the reflect linear positive mode and laser power of 60%.Under optimal conditions,the proposed MALDI-TOF MS method could obtain stable signal,high intensity and well-repeated mass spectrometric results.The results of method validation showed a linear range from 10 to 100 ng/mL,and the regression coefficients(r)were all above 0.985.The limits of detection(LOD)were 0.1-1.0 ng/mL,and the recoveries were in the range of 72.9%-109.9%for health wine,soft capsule and instant coffee samples,while the relative standard deviations(RSDs)ranged from 0.7%to 11.3%(n=3).The test results of 10 kinds of aphrodisiac drugs by MALDI-TOF MS were in accordance with the results of high-performance liquid chromatography-tandem mass spectrometry.This method exhibited high sensitivity,high accuracy,good anti-interference ability,low chemical solvents consumption and environmentally friendliness,and could be used to detect drugs without standards.The developed MALDI-TOF MS method could realize the non-target screening and detection of 10 kinds of illegally added aphrodisiac drugs in foods.

Widespread utilization of glyphosate has led to environmental residues,posing potential threats to ecological systems and human health.Traditional methods for detection of glyphosate are limited by specialized equipment and operational techniques,resulting in inefficient responses.Therefore,it is urgent to develop a convenient,sensitive and accurate detection method for detection of glyphosate.Herein,a new naphthalenesulfonamide-based"Turn-on"fluorescent probe was synthesized using 2-chloroaniline and dansyl chloride as raw materials through a one-step process,which showed a good linear relationship between the glyphosate concentration in concentration range of 0.003-70 μmol/L and the fluorescence intensity(R2=0.995),with a detection limit of 2.73 nmol/L(S/N=3).Analytical techniques such as nuclear magnetic resonance(NMR)spectroscopy and high-resolution mass spectrometry(HRMS)were used to investigate the interaction mechanism between the fluorescent probe and glyphosate.The results indicated that a nucleophilic substitution reaction occurred between the probe and the secondary amine(—NH—)of glyphosate,inducing a photoinduced electron transfer(PET)effect which enhanced the fluorescence intensity by 11.2 times.The probe showed good anti-interference ability towards coexisting metal ions,anions and pesticides in water.When applied to determination of glyphosate in the samples such as tap water,river water(Xiangxi River Reservoir),soil,soybeans,and corn,the spiking recoveries ranged from 94.7％to 109.9％,demonstrating the high accuracy and broad applicability of this detection method.A portable test strip based on this fluorescent probe was developed for rapid semi-quantitative analysis of glyphosate.The developed method was rapid,sensitive,and portable,providing theoretical and technical support for on-site measurement of environmental contaminants.